1. Field of the Invention
The invention relates to a bar feeder for feeding a bar material to a working machine such as lathe, to a feed rod vibration prevention support in a material feeder, and to a vibration stopper of the material feeder.
2. Related Art
A bar feeder of a related art includes a structure having a feed rod passing through a guide pipe in form of a U-groove or cylindrical pipe, or an oil feeder for supplying oil to such guide pipe.
On the other hand, another automatic rod feeder includes an oil feeder having bushes fastened by screws in the U-groove guide at a predetermined interval. This oil feeder includes a bush body and a screw for fixing the bush to a guide pipe.
The guide pipe of the first-mentioned bar feeder, however, has a continuous long-scale structure composed of a metal, a resin or a compound of these metal and resin. In this structure, even if the oil is fed to the guide pipe having a feed rod inserted therein, only a slight gap exists between the feed rod and the inner periphery of the guide pipes. Because of this reason, the oil hardly reaches the feed pipe guide portion, thereby achieving less vibration prevention effect. Where wearing occurred to parts, an entire structure was obliged to be exchanged because the guide pipe has the continuous structure.
In the guide pipe of the latter-mentioned rod feeder, on the other hand, when the oil is fed from an oil feed port, the oil is not fed to a space of a next oil reservoir as far as the oil goes over a wall of the bush. When a feed rod is placed on the bush, the space is closed by the feed rod, and accordingly, a slight gap remains between the feed rod and the inner periphery of the bush. Because of this reason, the oil reaches the neighbouring oil reservoir through this slight gap, so that it is difficult for the oil to reach the neighbouring oil reservoir, thereby reducing the vibration prevention effect due to the oil.
Another bar feeder of a related art includes a belt vibration stopper having upper and lower frames vertically opened or closed with two fulcrums being the centers thereof. Such machines or like are required to be adjusted in accordance with a diameter of the material. However, these machines or like are not provided with any mechanism for adjusting an open/close angle of the frames so as to accord with the material diameter. The upper and lower frames must be adjusted independently, which, however, is not easily performed. Especially, in a case where the lower and side surfaces of the upper and lower frames are covered by covers or like, it is predicted to be difficult to adjust the lower frame.
Furthermore, a roller vibration stopper of a related art has upper and lower frames opened or closed with one fulcrum being the center thereof. However, the upper and lower frames are used in the closed state, and this stopper is not provided with any mechanism for adjusting the open/close angle of the upper and lower frames so as to accord with the material diameter.
An oil support of a related art has a mechanism opened or closed vertically. The oil support is, however, not provided with a mechanism for adjusting the open/close angle so as to accord with the material diameter.
A roller vibration stopper of a related art has a frame opened or closed by two cylinders. However, a structure including such two cylinders is complicated and the vibration stopper is firmly fixed to a body.
Another bar feeder feeds a bar from its front end side to the working machine such as lathe while supporting the rear end of the bar material, and the working machine supports the rear portion of the bar material during the working of the front end portion of the bar material.
The bar feeder is provided with a support portion having a U-shaped groove. This support portion is located on the extension of a main shaft of the working machine, and the bar material fed in the U-shaped groove is fed to the main shaft of the working machine by a feed pipe reciprocating in the U-shaped groove.
The bar material is fed into the U-shaped groove from a material rack located on one side of the support portion, and a number of bar materials are arranged in parallel with the U-shaped groove. The bar materials are fed one by one from the material rack to the U-shaped groove of the support portion, and the bar material rolling down from the material rack is received in the U-shaped groove. As mentioned above, when the bar material is fed into the support portion, the feed pipe advances in the U-shaped groove to push the bar material toward the spindle of the working machine. The working machine works the front end of the bar material by repeating clamping and unclamping operations and sequentially cuts and feeds products so that each of them has a predetermined length. After the repeated cutting working, and one bar material is completely worked, a new bar material is fed from the material rack into the U-shaped groove of the support portion, and the like working is repeated.
Further, at the time when the bar material is fed from the material rack into the U-shaped groove of the support portion in the bar feeder, the bar material rolls down into the U-shaped groove, so that an impact, noise or like may be caused by the collision of the bar material with the support portion.
For example, in a case where the bar material is erroneously fed into the U-shaped groove by a miss-operation of an operator, it is extremely difficult to take out the bar material from the U-shaped groove. This difficulty will be increased in a case the diameter of the bar material becomes near the width of the U-shaped groove.
One end of the U-shaped groove of the support portion is opened, and accordingly, the bar material is easily come off from this open end of the U-shaped groove during the working of the bar material.